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2 sheetssh'eet 1 (No Model.)

A. B. HERRICK. ELECTRIC CURRENT INDICATOR. 7 No. 435,695. Patented Sept. 2, 1890 o 2 Sheets-Sheet 2.

(No Model.)

A. .B. HERRIGK. ELECTRIC CURRENT INDICATOR.

No. 435,695 Patented Sept. 2; 1890.

WITIIESSES: amid ATTORNEYS.

UNITED STATES [PATENT OFFICE.

ALBERT B. I-IERRICK, OF NEW YORK, N. Y., ASSIGNOR TO THE BERGMANN d6 COMPANY, .OF SAME PLACE.

ELECTRIC-CURRENT INDICATOR.

SPECIFICATION forming part of Letters Patent No. 435,695, dated September 2, 1890. Application filed March 13, 1890. Serial No. 848,689. (No model.)

To all whom it may concern: 7 is in turn connected with conductor 2 by an Be it known that I, ALBERT B. HERRICK, a angle extension, also having a curved surcitizen of the United States, residing at New face 5. It is obviously immaterial whether York, in the county and State of New York, the parts joining conductors 1, 6, 7, and 8 are 5 have invented an Improved Electric-Current formed integral with said conductors or are Indicator or Amperometer, of which the folseparate pieces suitably secured in place. lowing is a full and exact description. The piece joining conductors 6 and 7 at their Myinvention relates to devices for measurlower ends is also provided with a curved ining electric currents which are especially ner face. By this construction I provide a [0 adapted for use in connection with the heavisolenoid having a single turn or coil. The est currents used in the electrical arts, and passage through this coil will be substantially which are constructed substantially as hereinrectangular in cross-section and will be prefafter set forth. This indicator is operated erably much narrower in the direction at entirely by variations in the current measright angles to conductors 1 and 2 than in 15 ured, and is not dependent on the operation the other direction. 5

' of permanent or other magnets. In connection with certain features of my The indicator consists of the following invention a continuous conductor bent into parts: thick conducting bars or strips, preferthe form of a coil could be used; but in that ably rectangularin cross-section and having case the coil should be flattened, so as to give 20 two ends joined by means of conductors of a cross-section substantially like that above substantially the same cross-section or condescribed. The conductors are preferably ductivity as said bars in such manner as to painted or enameled, but are not otherwise form acurved rectangular passage, anda ring insulated, although a slight space is left becarrying a plate armature and controlling an tween the parts forming the coil, as shown.

25 indicating-hand movable over a graduated Pivoted at 8, generally on jeweled bearings, scale, all as will be hereinafter described. is the ring 3, before referred to. This ring is In the accompanying drawings, which illuspreferably of non-magnetic materialsuch as trate my invention, Figure 1 is a front elebrassand carries a segment-plate armature vation. Fig. 2 is a front elevation with apart 9, which extends partially around the ring 30 of the conductor and the indicating apparaand is normally held with one end in proxim- 8o tus removed. Fig. 3 is a side view of Fig. 1, ity to the conductor or coil by the weight 10. looking toward the right. The segment may consist of a single sheet of 1 2 are conducting-bars for the current to iron, or may consist of several sheets placed be measured. In practice I have made these side by side, forming a laminated armature.

5 about one by two inches, in order to provide 011 the same axis as wheel 3 is an indicata conducting-path of very low resistance. ing hand or pointer 11, which is normally These bars are preferably placed at an angle held at the zero-point on scale 12 by the to each other, and their approaching ends are weight on the ring. The scale 12 is prefery joined as follows: Conductor 1, which is bent ably graduated to indicate amperes, so that o upwardly so as to pass above the ring 3, is at any moment the strength of current on the connected at its end with an angle extension line may be read on the scale by observing at, which extension is provided with a curved the position .of the index-pointer. I have innerface 5. This extension in turn connects shown the scale below the axis; but it would with a conducting-piece 6, which extends in a evidently be an equivalent arrangement to 5 line substantially parallel with the conductor place it above the ring and reverse the direc- 2 and which passes beneath said ring 3. At tion of the pointer. the lower end of conductor 6 is also an angle 13 is a stop against which the radial arm extension connecting with a conducting-piece carrying ring 3 strikes to limit its motion in 7, which extends substantially parallel with one direction.

50 the conductor 1. The upper end of conductor Instead of making the ring continuous it may be broken away at 14 let, as indicated by the dotted lines in Fig. 1, and the armature plate 9 may complete the ring between those points.

The Weight which I have shown consists of a coil of wire-such as lead wire-wound directly upon the ring; butI do not confine myself to this form. I may have an adjustable weight, as indicated in dotted lines at 15, which weight may be placed below the radial arm, 0r,if space be left between said arm and the armature-plate, may be placed above the arm.

In using this indicator current enters conductor 1 and passes through the apparatus, as indicated by the arrows. This current creates a magnetic field the strength of which is direotlydependent upon the current. Armature 9, being delicately suspended, is attracted by the field, and moves the pointer 11 over the scale 12, which, when the apparatus was made, was subdivided and marked to indicate amperes, as before stated. An increase in the current moves the pointer farther on the scale. A decrease in the current allows the weight to move the pointer in a reverse direction, and as soon as current ceases to flow the weight carries the armature and pointer back to their original positions. By employing thick conductors with a single turn and the plate armature mounted, as described, I am enabled to measure very heavy currents as readily as Weaker currents have been heretofore measured, and such measurement does not involve complicated and expensive ap paratus.

Having thus described my invention, what I claim is 1. The combination, in an electric-current indicator, of a coil, a pivoted ring movable therein, and a plate-armature carried by the ring, substantially as described.

2. The combination, in an electric-current indicator, of a coil, a pivoted ring passing through the coil, a plate-armature carried by said ring, and a pointer connected to the ring and moving therewith, substantially as described.

3. The combination, in an electric-current indicator, of a coil constituting a portion of the circuit, a pivoted ring passing through said coil and having an index-pointer, and a magnetic plate on said ring constituting the core or armature, substantially as described.

4. The combination, in an electric-current indicator, of a coil consisting of a heavy conducting-bar, an angle extension, a second bar having an opposite extension, and two bars at an angle with each other and with said first bars but joining the same, thereby forming a single turn or coil, and a plate-armature passing through the same and controlling the index-pointer, substantially as described.

5. The combination, in an electric-current indicator, of two conducting-bars at an angle with each other, their approaching ends connected to form a turn or coil, a plate-armature movable in said coil, and an indicating device connected with and moved thereby, substantially as described.

6. The combination, in an electric-current indicator, of two conducting-bars at an angle with each other, their projecting ends connected to form a coil, a pivoted segment-plate armature controlling a pointer. and a graduated scale over which the pointer moves, substantially as described.

This specification signed and witnessed this 8th day of March, 1890.

ALBERT B. HERRICK. Witnesses: W. E. MooRE,

CHAS. E. ESTABROOK. 

